The invention relates to a device for locking the locking bolt of a cylinder lock in its locked position when an unauthorised removal of the lock cylinder is effected, which device comprises a lever which rests against a portion of the locking cylinder and which is swivelled upon the removal of the locking cylinder.
For the forced manipulation of cylinder locks, it is known practice to pull the locking cylinder therefrom and to press back the locking bolt through the opening which has then been formed. In order to prevent this happening, it is known to allow the locking cylinder to engage in the lock housing in an unreleasable manner ("buttoning-in"). Moreover, it is known from German Offenlegungsschrift No. 2,252,743 to prevent the locking bolt being pressed back in that there is arranged in the lock housing at the rearward end of the locking bolt a lever which rests against the cylinder core shift roller when the locking bolt locks and tilts, when the locking cylinder has been pulled out, to a position in which it prevents the locking bolt from being pressed back. Since this known lever is also moved during the cylinder core locking movements, it is relatively complicated and elaborate in design and therefore susceptible to trouble. Moreover, when the locking cylinder has been pulled out, this lever can also be manipulated in a manner similar to the locking bolt, and furthermore it is possible for the lever to be inadvertently moved to the locking position during the installation of the lock, thus making dismantling necessary.
It is the object of the invention to improve a device of the kind mentioned at the beginning in such a way that it is simple in construction, cannot be manipulated when the locking cylinder has been withdrawn and is easy to install.